webadmin : Hide cluster logical networks virt actions in Gluster mode

The menu options like "Add Network", "Manage
Networks" and "Set as Display" and the dialogues coming from these
menu options, are not applicable to RHS.So,this patch hides them
in Gluster only mode.

Change-Id: I2436c11b51f6707c70aef426e1e253ff958fa6dd
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1015020
Signed-off-by: Anmol Babu <anbabu@redhat.com>